Pivoted angular bender



Nov; 8, 1949 B. A. WOINA PIVOTED ANGULAR BENDER 4 Sheets-Sheet 1 Filed June 10, 1946 INVENTOR. 557 007? /4. Wama ArrakA/sy-s Nov, 8, 1949 B. A. WOINA 2,487,747

PIVO'I'ED ANGULAR BENDER Filed June 1o, 1946 4 Shets-Sheet 2 FIG. 5.

A Tfa/ENEYS Nov. 8, 1949 A. wo 2,487,747

PIVOTED ANGULAR BENDER Filed June 10, 1946 4 Sheets-Sheet 3 ATTORNEYS Nov. 8, 1949 B. A. WOINA PIVOTED ANGULAR BENDER 4 Sheets-Sheet 4 Filed June 10, 1946 FIE-.7.

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ATTORNEYJ Patented Nov. 8, 1949 UNIT so "STATE 5 2,487,447

"PIVOTED ANG-ULAR BENDER Benjamin A; -Woina, Salem} hio, assignor to Mullins Manufacturing} (lorporatiom Salem,

"ohioga corporation of NewYork Application June 10, 1946, Serial N6. 675,659

'3 Claims.

. 1 V This invention relates to a sheet metal forming apparatus and more particularly to a device for forming sharp cornered bends. In the construc- "tion of metal'cabinets, furniture and similar arti'cles," the formation of sharp corners, usually right-angle corners, has heretofore been per- "formed by die pressing or in a sheet metal brake. 'Where a flat or formed sheet metal piece is to be given one or more right-angled or other sharp cornered bends, these" methods are sometimes "cumbersome or difficult to'apply.

It is an object of the present invention to provide an improved bending apparatus in which a sharp cornered bend may be readily formed in a strip or sheet of metal, for example, one having upturned flanges such as a channel member.

A further object is to provide a device of this character wherein a forming head of simple and compact construction may be utilized andwhich is soarranged that a plurality of such heads may be located at different corners of a 'die block around which a sheet is to be formed with several sharp cornered bends.

" Figure l is a plan view of a metal bending "apparatus incorporatingapreferred form of the "present invention.

"*"Fi'gureZ is a perspective view of a typical work "piece after forming.

"Figure 3 is a view corresponding to'Figure 1 showing the parts in a'difler'ent position. 'Figure4 is a plan view of a metal bending flxture incorporating several of the forming heads illustrated in Figures 1 and 3.

Figurefi isa partial s'ection ensues- 5 of Figure 1.

Figure-6 is apartial-section'on line 6-6 of Figure 1.

Figure 7 is a view taken on line l--'| of Fig- "ure 1.

37? Figure 8 is a view taken on line 8-8 of Fig- "ure 1.

Figure 9 is a sectional view on line -9--9 of Fig- "ure 3.

Referring nowto-Figure 2 there is shown a 'ing part of a conventional fluid operating cylinder. The head l6may be guided 0n stationary ways 20. Rigidlyassociated with the ways is a*stationary die block 22 having" oneo'r more right-angled sharp corners" 24, 26 and" 28 about which the work piece is to be formed. The main head I6 has securedthereto or formed integrally therewith a cam member 30 having an inclined and curved cam face 32for a purpose later to bedescribed. slidably and yieldably associated with the forminghead I6 is a'hold-down-plate 34. The latter may be guided 0n suitable'dowels 36-and bushings secured to *the "forminghead l6. Suitable headed retainers 40 also secured to the head lfiiimit the separation between head lfi and hold-down block 34. Positioned in recesses' 42 are a -plu'rality' of compression springs '44 which normally urge the hold-downblock 34 at its maximum extension from the head l-B as shown in Figure 3. The hold-down block may have flanged portions 46 adapted to'overlie =the flanges l2 of 'the work piece ID as shown more clearly in Figure 5. Pivoted on studs 48 in the flanges 46 is a rocker plate 50 (see Figure 6) which may also haveupturned" flanges 52- on its righthandface Figure 3'and flanges 54'on its lefthand face in Figure 3 The latter-are adapted to overlie the flanges of the work piece while the iormer are contacted bythe cam face 32 and "provide clearance for a'sp'rin'g 56 which normally i retains the rocker plate in theposition illustrated in Figure 3. In Figure 9 the flanges 52 and 5 -are shown in-cross-section. The pivot studs 48 are accurately positioned so that the pivoting "axis will-lie substantially on the corner 24 except that it is spaced upwardly and rightwardly therefrom; in Figure 1,by the "thickness of'the "sheet metal work piece.

In operation, considering the action of "a' single forming head as illustrated in' Figuresl and 3,

the'head'when projected'to the left from the position shown in Figure '3 will bring the hold-down block 34'intdcontactwith' a work piece In which is positioned upon the stationary die block 22; a portion of the work piece overhanging upwardly above the corner 24. Thereafter further movement of the forming head l6 driven by the piston rod I8 will compress the springs 44. At the same time, the cam block 30 will contact the rocker plate 50 along the flanges 54 swinging it counterclockwise to the position illustrated in Figure 1. This carries the overhanging end of the work piece with it and wraps the same snugly around the corner 24 of the die block 22. The flanges 52 of the rocker plate as well as the flanges 4B of the hold-down block serve to retain the flanges [2 of the work piece during this operation. The cam block 30 is shaped to contact rocker plate 50 at its outer end where the most leverage is obtained for the initial movement. The contact moves inward to full contact and still further toward the pivot point 48 as movement progresses. At the same time, the hold-down block firmly grips the work piece and clamps it to prevent displacement thereof during the bending operation.

Upon retraction of the piston rod l8 and head IS, the cam block 30 will permit spring 56 to restore rocker plate 50 to its former position and after a predetermined retraction will pick up the hold-down block 34 returning it to the position illustrated in Figure 3.

As seen more particularly in Figure 4, a plurality of similar forming heads together with their guide ways and actuating cylinders may be mounted at the various corners of the die block 22. Thus a straight flanged work piece may be progressively bent first at one corner and then at the next proceeding counterclockwise around the die block. For this purpose, suitable automatic sequence controls for the actuating cylinders wel1-known in the art may be provided.

It will thus be seen that the present invention has provided a simple rugged forming tool which is compact and self-contained. Likewise, it is particularly adapted to the construction of special bending machines for forming one particular size part to a given contour in that the forming heads are inexpensive and may be used over again in other setups when the usefulness of a given setup has endedv The heads are also well adapted for use with simple fixtures in a press of conventional construction, in which case, a single die block may be mounted rotatably on an axis perpendicular to the press ram movement and indexed progressively to properly position the corners thereof sequentially under a single forming head.

I claim:

1. A sheet metal forming device comprising 'a die block having two angularly related flat surfaces meeting in a sharp external corner, and a forming head, said die block and head being mounted for movement of one relative to the other perpendicularly to one of the flat surfaces, a hold-down block yieldably carried by the forming head to clamp a Work piece against said one surface with a portion overhanging the corner, a rocker plate pivoted to the hold-down block on an axis coincident with the outside corner of the work piece when formed, and a cam block rigidly secured to the forming head for pivoting the rocker plate and the overhanging part of the work piece around the corner of the die block.

2. A sheet metal forming device comprising a die block having two angularly related surfaces meeting in a sharp external corner, and a forming head comprising a hold-down block yieldably 4 carried by the forming head to clamp a work piece against one surface with a portion overhanging the corner, said die block and head being mounted for movement of one relative to the other perpendicularly to one of the surfaces, a rocker plate pivoted to the hold-down block on an axis coincident with the outside corner of the work piece when formed, and a cam block rigidly secured to the forming head for pivoting the rocker plate and the overhanging part of the work piece around the corner of the die block as the forming head moves toward the die block,

the cam block having an angular surface projecting forward to contact the rocker plate initially at a point remote from the axis of pivot and arranged to bear entirely on the plate during one point of travel and to shift the pressure point inward toward the axis as the movement progresses.

3. A sheet metal forming device comprising a die block having two angularly related surfaces meeting in a sharp external corner, and a forming head comprising aliold-down block yieldably carried by the forming head to clamp a work piece against one surface with a portion overhanging the corner, said die block and head being mounted for movement of one relative to the other perpendicularly to one of the surfaces, a rocker plate pivoted to the hold-down block on an axis coincident with the outside corner of the work piece when formed, and a cam block rigidly secured to the forming head for pivoting the rocker plate and the overhanging part of the work piece around the corner of the die block as the forming head moves toward the die block, the cam block having an angular surface projecting forward to contact the rocker plate initially at a point remote from the axis of pivot and arranged to bear entirely on the plate during one point of travel and to shift the pressure point inward toward the axis as the movement progresses, the rocker plate having a pair of flanges on opposed sides, one pair being positioned to overlie the work piece at the die block and the other pair being positioned to contact the cam block, and a return spring fastened at one end to the hold-down block and at the other end to the rocker plate in the recess between the last named pair of flanges to return the rocker plate to initial position.

BENJAMIN A. WOINA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 65,987 Allison June 25, 1867 972,195 Jacobs Oct. 11, 1910 1,323,143 Abbott Nov. 25, 1919 1,527,375 Nystrom Feb. 24, 1925 2,272,740 Fader Feb. 10, 1942 2,287,933 Greene June 30, 1942 

